The Lihir Gold Mine is one of the world’s largest gold producers, located on Niolam Island in the Lihir Island group of Papua New Guinea, approximately 900 km northeast of Port Moresby. The mine operates within the geothermally active Luise Caldera, an extinct volcanic crater hosting one of the largest known gold deposits globally.
Key points about the Lihir Gold Mine:
Ownership and management: since 2010, the mine has been owned and operated by Newcrest Mining, following their acquisition of Lihir Gold Limited. Previously, Rio Tinto managed the mine until 2005 before Lihir Gold took over.
Geology and mineralization: the deposit is a hydrothermally altered porphyry gold system with gold mostly contained in sulphides within volcanics, intrusive, and breccias. The gold mineralization occurs primarily within several deposits in the caldera, named Lienetz, Minifie, Coastal, and Kapit. The orebody is refractory, requiring pressure oxidation before cyanide leaching to extract gold.
Reserves and resources: as of recent data, Lihir holds about 17.5 million ounces of gold reserves and over 20 million ounces of gold resources. The mine has proven, and probable reserves estimated at around 310-380 million tonnes grading approximately 2.3-2.4 grams per tonne gold.
Production and life: the mine has produced over 9 million ounces since production started in 1997. In 2023, it produced approximately 670,000 ounces, with ongoing production expected for another 16 years or more. The recent Phase 14A expansion aims to access additional high-grade ore and extend the mine’s life and output.
Mining and processing: Lihir is an open-pit operation with two adjacent overlapping pits. The mining fleet includes large shovels and haul trucks. Ore processing involves crushing, grinding, flotation, pressure oxidation, and conventional leaching to recover gold. The processing plant has a capacity exceeding 15 million tonnes per annum, with upgrades to improve output, reduce costs, and increase gold recoveries.
Environmental and social: tailings are managed by deep-sea placement in a deep-ocean location. The mine employs thousands of residents and fly-in-fly-out workers, contributing significant economic value and royalties to Papua New Guinea.
In summary, the Lihir Gold Mine is a large, long-life open-pit gold mine set in an extinct but geothermally active volcanic caldera, known for its refractory high-grade ore and substantial gold reserves, operated by Newcrest Mining in Papua New Guinea.
